<?php
/*
 *
 * Stan Scates
 * blr | further
 *
 * stan@sc8s.com
 * blrfurther.com
 *
 * Basic OAuth and caching layer for Seaofclouds' tweet.js, designed
 * to introduce compatibility with Twitter's v1.1 API.
 *
 * Version: 1.4
 * Created: 2013.02.20
 *
 * https://github.com/seaofclouds/tweet
 * https://github.com/themattharris/tmhOAuth
 *
 */
if (empty($_POST)) {
    die();
}

class ezTweet
{

    /**
     * ************************************* config **************************************
     */
    
    // Your Twitter App Consumer Key
    private $consumer_key = 'YOUR_CONSUMER_KEY';
    
    // Your Twitter App Consumer Secret
    private $consumer_secret = 'YOUR_CONSUMER_SECRET';
    
    // Your Twitter App Access Token
    private $user_token = 'YOUR_ACCESS_TOKEN';
    
    // Your Twitter App Access Token Secret
    private $user_secret = 'YOUR_ACCESS_TOKEN_SECRET';
    
    // Path to tmhOAuth libraries
    private $lib = './lib/';
    
    // Enable caching
    private $cache_enabled = true;
    
    // Cache interval (minutes)
    private $cache_interval = 15;
    
    // Path to writable cache directory
    private $cache_dir = './';
    
    // Enable debugging
    private $debug = false;

    /**
     * ***********************************************************************************
     */
    public function __construct()
    {
        // Initialize paths and etc.
        $this->pathify($this->cache_dir);
        $this->pathify($this->lib);
        $this->message = '';
        
        // Set server-side debug params
        if ($this->debug === true) {
            error_reporting(- 1);
        } else {
            error_reporting(0);
        }
    }

    public function fetch()
    {
        echo json_encode(array(
            'response' => json_decode($this->getJSON(), true),
            'message' => ($this->debug) ? $this->message : false
        ));
    }

    private function getJSON()
    {
        if ($this->cache_enabled === true) {
            $CFID = $this->generateCFID();
            $cache_file = $this->cache_dir . $CFID;
            
            if (file_exists($cache_file) && (filemtime($cache_file) > (time() - 60 * intval($this->cache_interval)))) {
                return file_get_contents($cache_file, FILE_USE_INCLUDE_PATH);
            } else {
                
                $JSONraw = $this->getTwitterJSON();
                $JSON = $JSONraw['response'];
                
                // Don't write a bad cache file if there was a CURL error
                if ($JSONraw['errno'] != 0) {
                    $this->consoleDebug($JSONraw['error']);
                    return $JSON;
                }
                
                if ($this->debug === true) {
                    // Check for twitter-side errors
                    $pj = json_decode($JSON, true);
                    if (isset($pj['errors'])) {
                        foreach ($pj['errors'] as $error) {
                            $message = 'Twitter Error: "' . $error['message'] . '", Error Code #' . $error['code'];
                            $this->consoleDebug($message);
                        }
                        return false;
                    }
                }
                
                if (is_writable($this->cache_dir) && $JSONraw) {
                    if (file_put_contents($cache_file, $JSON, LOCK_EX) === false) {
                        $this->consoleDebug("Error writing cache file");
                    }
                } else {
                    $this->consoleDebug("Cache directory is not writable");
                }
                return $JSON;
            }
        } else {
            $JSONraw = $this->getTwitterJSON();
            
            if ($this->debug === true) {
                // Check for CURL errors
                if ($JSONraw['errno'] != 0) {
                    $this->consoleDebug($JSONraw['error']);
                }
                
                // Check for twitter-side errors
                $pj = json_decode($JSONraw['response'], true);
                if (isset($pj['errors'])) {
                    foreach ($pj['errors'] as $error) {
                        $message = 'Twitter Error: "' . $error['message'] . '", Error Code #' . $error['code'];
                        $this->consoleDebug($message);
                    }
                    return false;
                }
            }
            return $JSONraw['response'];
        }
    }

    private function getTwitterJSON()
    {
        require $this->lib . 'tmhOAuth.php';
        require $this->lib . 'tmhUtilities.php';
        
        $tmhOAuth = new tmhOAuth(array(
            'host' => $_POST['request']['host'],
            'consumer_key' => $this->consumer_key,
            'consumer_secret' => $this->consumer_secret,
            'user_token' => $this->user_token,
            'user_secret' => $this->user_secret,
            'curl_ssl_verifypeer' => false
        ));
        
        $url = $_POST['request']['url'];
        $params = $_POST['request']['parameters'];
        
        $tmhOAuth->request('GET', $tmhOAuth->url($url), $params);
        return $tmhOAuth->response;
    }

    private function generateCFID()
    {
        // The unique cached filename ID
        return md5(serialize($_POST)) . '.json';
    }

    private function pathify(&$path)
    {
        // Ensures our user-specified paths are up to snuff
        $path = realpath($path) . '/';
    }

    private function consoleDebug($message)
    {
        if ($this->debug === true) {
            $this->message .= 'tweet.js: ' . $message . "\n";
        }
    }
}

$ezTweet = new ezTweet();
$ezTweet->fetch();

?>
